The present invention generally relates to sewage treatment and specifically to high concentration waste which cannot be accommodated by common municipal-type waste treatment facilitates and to situations which require waste treatment immediately and until municipal-type waste treatment can be provided.
Discharge standards for waste treatment facilities are closely regulated by various governmental agencies. A standard unit of measure is the biological oxygen demand (BOD) loading concentration, commonly given in units of parts per million (ppm). in the inventor's home state of Michigan, for example, the BOD for secondary municipal-type waste treatment facility discharge is limited to 20-30 ppm. This typically mandates a BOD less than 250 ppm in the sanitary sewer which supplies the municipal-type waste treatment facility, in order to avoid overloading and shocking the treatment facility system.
Waste treatment facilities are typically designed to accommodate specified volumes of waste at a specific BOD. The mandated maximum BOD limit typically accommodates residential sanitary sewer systems at volumes which do not exceed design capacities of the specific municipal-type waste treatment facility used. However, the capacity of a municipal-type waste treatment facility is commonly met and exceeded by growing surrounding communities. Thus, the situation of a municipal waste treatment facility only marginally accommodating the treatment requirements of the community or actually operating outside of specification is a common occurrence. Further, with such high community demand, the municipal facility cannot further accommodate sources of high concentration waste, including, but not limited to, landfill leachate, septage, and holding tank waste, for example.
Leachate typically has a BOD of about 5,000 ppm with septage typically having about a 3,500 ppm BOD. Clearly, these are far beyond and cannot be accommodated by the typical .municipal-type waste treatment maximum BOD limit of about 250 ppm. Further, holding tank waste presents a different problem, namely excessive amounts of macroscopic solid waste which may typically account for up to 40 percent of a holding tank's contents.
Another waste treatment problem occurs when municipal waste treatment connection is simply not available and the alternative use of a holding tank and drainage field is inappropriate. One solution to the unavailability of municipal treatment is to truck the waste from the sight of origin to a treatment facility. However, this is often a costly proposition.
A common method of disposal for each of the above identified sources of waste, including high concentration waste, is to simply spread the waste over an open field, such as a farm field. This presents further problems. First, nitrates, commonly found in high concentrations in this waste, quickly filter through the ground and settle into ground water tables, potentially and likely polluting the ground water. Second, even if buried or cultivated into the soil, solid wastes have a tendency to "float" up through and surface above the ground. Finally, monitoring and regulating the disposal of heavy metal and toxic waste is particularly difficult in surface dispersion programs with significant ground and water pollution problems resulting.